Public Health Nutrition: page 1 of 8
doi:10.1017/S136898001200064X
Health labelling can influence taste perception and use of table
salt for reduced-sodium products
Djin Gie Liem1,*, Fatemeh Miremadi1, Elizabeth H Zandstra2 and Russell SJ Keast1
1
School of Exercise and Nutrition Sciences, Sensory Science Group, Faculty of Health, Deakin University,
Burwood Highway, Burwood, VIC 3125, Australia: 2Sensation, Perception & Behaviour, Unilever R&D
Vlaardingen, Vlaardingen, The Netherlands
Public Health Nutrition
Submitted 21 September 2011: Accepted 20 January 2012
Abstract
Objective: To investigate the effect of front-of-pack labels on taste perception and
use of table salt for currently available and sodium-reduced soups.
Design: Within-subject design.
Setting: Sensory laboratory.
Subjects: Participants (n 50, mean age 34?8 (SD 13?6) years) were randomly served
nine soups (250 ml each) across 3 d. Servings differed in: (i) health label (i.e. no
health label, reduced-salt label or Heart Foundation Tick); and (ii) sodium
reduction (no reduction – benchmark, 15 % less sodium or 30 % less sodium).
Before tasting, participants rated their expected salt intensity and liking. After
tasting, participants rated their perceived salt intensity and liking, after which they
could add salt to the soup to make it more palatable.
Results: Reduced-salt labels generated a negative taste expectation and actual taste
experience in terms of liking (P , 0?05) and perceived saltiness (P , 0?05). Perceived
saltiness of sodium-reduced soups decreased more (P , 0?05), and consumers added
more salt (P , 0?05), when soups carried the reduced-salt label. The tick logo and
soups without health labels had no such influence on taste perception.
Conclusions: Emphasizing salt reduction by means of a front-of-pack label can have
a negative effect on taste perception and salt use, especially when consumers are
able to taste differences between their regular soup and the sodium-reduced soup.
Overall health logos which do not emphasize the reduction in salt are less likely to
affect perceived salt intensity and therefore are viable solutions to indicate the
healthiness of sodium-reduced products.
Australian consumers are well informed and seem to be
increasingly aware of the association between diet and
health(1). A recent study suggests that 88 % of Australian
consumers are aware of the association between high
sodium intake and elevated blood pressure, but a minority
(44 %) were worried about their sodium intake or were
aware (27 %) of the upper limit of daily sodium intake set by
the Australian National Heart Foundation(2), which makes it
difficult for them to understand nutrition information panels
which are placed on food products.
To assist consumers in making healthier food choices
several initiatives are taken. First, some food products
carry nutrient labels on the front of the pack, such as
‘low in salt’(3), which may attract the attention of healthconscious consumers(3,4). In Australia nutrient claims and
labels are regulated by the Australia New Zealand Food
Standards Code which, for example, states that a ‘low salt’
label is only permitted on foods which do not contain
more than 120 mg Na/100 g food(5). Health claims in
relation to sodium reduction are not permitted by the
*Corresponding author: Email [email protected]
Keywords
Salt
Taste
Consumer
Labelling
Soup
Expectation
Liking
Desire
Code. Second, some food products carry a front-of-pack
health logo, which enables consumers to make quick and
healthier food choices(6,7). In 1989 the Australian Heart
Foundation initiated the ‘Pick-the-Tick’ programme. A
manufacturer can apply for a Tick by submitting a proposal
to the Heart Foundation, which reviews the proposal
according to predetermined criteria (see (8,9)). Ten years
after the introduction of the Pick-the-Tick programme, 89 %
of Australian consumers recognized the Tick logo and the
majority (59 %) reported to buy products with this logo(9).
Although nutrient labels as well as health logos aim to
assist consumers in making a healthier choice, they may not
attract consumers who are more concerned about taste than
health. It has been suggested that health-conscious consumers are more likely to buy products with healthy choices
logos compared with taste-focused consumers(10). This may
generate a potential unexpected side-effect of nutrient
labels and healthy choice logos. Some consumers may
deliberately avoid products with nutrient labels and/or
healthy choice logos, because they expect these products to
r The Authors 2012
2
DG Liem et al.
Public Health Nutrition
(6)
be inferior in taste . Information given alongside food may
trigger different areas of the brain in such a way that
information associated with a bad taste triggers brain areas
also known to be activated by the smell of a bad odour(11).
In a study with margarines, it was found that consumers
who held positive beliefs about full-fat spread judged margarines which carried a ‘full fat’ label as more pleasant,
smoother and having better mouthfeel than identical margarines which were labelled as ‘reduced fat’(12). Similar
results were also obtained with soups(13). We previously
suggested that labels such as ‘reduced in salt’ negatively
impacted on expected saltiness, but not perceived saltiness
of non-sodium-reduced soups(14). It is yet unknown how
nutrient labels and healthy choices logos affect the perception of products which are noticeably different from
consumers’ normal products due, for example, to sodium
reduction.
Hypothetically, the discrepancy in terms of liking and
perceived saltiness between consumers’ normal product and
the reduced-sodium product can be increased when consumers expect products to be less salty and/or tasty. This is
called assimilation. During assimilation, consumers’ perception is biased towards their expectations(15,16). Lange et al.
suggested that when differences (induced by the type of
information) between blind ratings and expectations of
identical orange juices were large, consumers moved their
ratings towards their expectations(17). A similar phenomenon
may happen when consumers taste a variety of sodiumreduced soups while seeing different health- and nutrientrelated labels, which alter consumers’ expectations of the
taste of the products in the direction of their expectations.
The present study investigated the influence of nutrient
labels (i.e. ‘Now reduced in salt, great taste’) and a health
logo (i.e. Pick-the-Tick) on expected and perceived taste
perception of sodium-reduced soups. It is hypothesized
that with an increase in sodium reduction, the negative
taste effects of a nutrient label and health logo will
increase as well.
Experimental methods
Participants
Participants were recruited by means of flyers in public
places. Those who reported to be allergic to the ingredients present in the test products were excluded. This
resulted in fifty participants (thirty-three females; mean
age 34?8 (SD 13?6) years) who completed all sessions for
which they received a $AUD 15 gift voucher after each
session. The study was approved by the Human Ethics
Committee of Deakin University (HEAG-H 180/09).
Materials
Soups
Three soups varying in sodium content were included in
the study: (i) benchmark product, which was an Australian
commercially available chicken noodle soup (305 mg Na/
100 ml prepared soup); (ii) 15 % sodium-reduced soup
(259 mg Na/100 ml prepared soup); and (iii) 30 % sodiumreduced soup (213 mg Na/100 ml prepared soup. The recipe
for all soups was the same (per 100 ml prepared soup:
energy 75?2 kJ, protein 0?44 g, total fat 0?24 g, saturated fat
0?04 g, carbohydrates 3?4 g, sugar 0?6 g); only the sodium
content was different. All soups contained: noodles, maltodextrin, salt, sugar, flavours (containing milk derivatives),
flavour enhancers (621, 627), sunflower oil, parsley, potassium chloride, turmeric and spice extract. The soups were
especially produced for the purpose of the current study
(Unilever Sydney, Australia).
Quantitative Descriptive Analysis was performed with
seven trained panellists (six females, mean age 51 (SD 15)
years) to assess sensory profiles (see Meilgaard et al.(18) for
more details). This resulted in seventeen attributes to
describe the flavour of the soup. Individual sensory testing
of the three chicken noodle soups (i.e. benchmark, 215 %
and 230 % sodium reduction), in duplicate, commenced
once panellists were able to rate the intensity of the
seventeen attributes reliably within and between panellists
(see Meilgaard et al.(18) for more details). Figure 1 shows
the sensory profile of the three chicken noodle soups.
Labels, bowls and salt shakers
Professionally produced labels (Red Gecko Design, Sydney,
Australia) were placed on the different pouches of dry
soups in such a way that the experimental labels had a
similar layout and look to the commercially sourced soup
labels. Soups (benchmark, 215 % and 230 % sodium
reduction) were provided with one of the three different
labels: (i) no health label; (ii) a nutrient label stating ‘Now
reduced in salt, great taste’ (hereafter referred to as the
‘reduced-salt label’); and (iii) a health logo, the Heart
Foundation Tick (hereafter referred to as the ‘tick label’; see
Fig. 2). Each combination of label and soup was given once
(3 labels 3 3 soups), which resulted in nine samples for
tasting. Soups were tasted from polystyrene double-layered
bowls, which were designed to minimize the cooling down
of the soups and could hold up to 350 ml of soup. Plastic
spoons were provided to the participants. Furthermore,
participants were provided with commercially sourced salt
shakers which contained 50 g of salt (Saxa table salt shakers,
8 cm 3 4 cm, nine holes). Salt shakers were weighed, on a
digital scale with microgram accuracy (model X3-310D;
Denver Instrument), before and after participants tasted
the soup. The salt shaker provided on average 0?04 g salt
per shake.
Sensory measures
Expected and perceived saltiness were measured with a
9-point just-about-right scale which combines intensity
and hedonic judgements and was previously designed
to assess consumers’ response to a specific attribute(19).
On this scale 1 5 ‘not salty enough at all’, 5 5 ‘just about
Effect of labels on taste and salt use
3
Balance
14
Leach
Fullness
12
Roasted grain
Salty (aroma)
10
8
Burnt protein
Caramelized
sugar
6
4
2
Chicken fat
Fatty mouthfeel
0
Sour mouthfeel
Chicken roasted
Sweet
Chicken boiled
Control
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Umami
Salty
Sour
Bitter
15 % sodium
reduced
30 % sodium
reduced
Fig. 1 (colour online) Sensory profile of the benchmark, 15 % and 30 % sodium-reduced soups as determined by Quantitative
Descriptive Analysis among seven panellists (0 5 ‘not strong at all’, 14 5 ‘extremely strong’)
Fig. 2 (colour online) Packages (left, no health label; middle, reduced-salt label; right, tick label) that were shown to the participants
prior to and during the tasting of the soups
the right amount of salt for me’ and 9 5 ‘far too salty for
me’. Expected and perceived liking were measured with a
9-point hedonic scale ranging from 1 5 ‘not liked at all’ to
9 5 ‘extremely liked’. All sensory data were collected
using CompuSense software version 5 (Compusense Inc.,
Guelph, ON, Canada).
Procedure
Consumers came to the university for a half-hour session
on the same day and time once weekly for 3 weeks. Tasting
took place in the sensory booths of the university, which
minimized interaction between participants while they
tasted the soups. At the start of each session participants
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4
were shown a package of soup and were asked whether
they would like to buy this soup and what they expected of
the liking, desire and saltiness of this soup. Subsequently,
they were instructed to open the pack and empty the
content in a soup bowl. The researcher then added boiling
water to a total of one serving (250 ml) of soup. Participants
were instructed to taste one spoonful of the soup when it
was cooled down to about 658C, which was verified with a
laser thermometer for each soup (model VZ8895NL, range
240 to 8008C; AZ Instruments). While tasting the soup,
participants were asked to rate the soup on perceived liking
and salt intensity. After tasting and rating the soup, participants were given a salt shaker with 50 g of salt and
were instructed to add as much salt as they wanted up to
their maximum liking. Participants were allowed to taste
the soup while they were adding salt and were free to
decide not to add any salt at all. In total, participants tasted
nine soups in a randomized order during three sessions on
three separate days in such way that they received one
pack with no label, one pack with the reduced-salt label
and one pack with the tick label each day. Every consumer
received a unique order; no order was given more than
once. Between sessions, participants were instructed to
rinse their mouth with water three times.
Statistical analysis
To assess the strength and direction of the association
between expectations and actual perception, Spearman
correlation coefficients were calculated between expected liking and perceived liking and between expected salt
intensity and perceived salt intensity. In order to determine differences in expected liking, one-way repeatedmeasures ANOVA (according to the within-subject design)
were conducted to determine significant differences between
(i) soups with different labels and (ii) soups with the same
label given during the three testing days. A similar analysis
was conducted to determine differences in perceived liking
after participants tasted the soups.
We hypothesized that consumers were more likely to
buy and consume a soup with an ideal saltiness than a soup
with a less ideal saltiness, so therefore it was important
to assess whether soups were perceived as significantly
different from their ideal saltiness. In order to determine
whether the expected and perceived salt intensity significantly differed from the ‘just about right’ value of 5,
one-sample t tests were conducted with 5 as the set value.
For those who added salt after tasting the soups, a
sodium compensation score was calculated by adding the
amount of sodium consumers added to the amount of
sodium present in the soup; this resulted in the total
amount of sodium. The total amount of sodium was then
expressed as a percentage of the total amount of sodium
present in the benchmark minus 100. For example, if a
participant added 250 mg of NaCl to 250 ml of the 215 %
sodium-reduced soup, the amount of sodium added 5
0?25 3 39?3 5 98 mg Na/250 ml soup. This amount was
DG Liem et al.
added to that in 250 ml of 215 % sodium-reduced
soup, which contained 648?1 mg Na/250 ml soup. Thus
the total amount of sodium 5 648?1 mg 1 98 mg 5 746?1
mg Na/250 ml soup. The benchmark soup contained
762?5 mg Na/250 ml soup. The compensation percentage 5 [(746?1/762?5) 3 100 %] 2100 5 23 %. This means
that after this participant added salt to the 215 % reducedsodium soup, the soup contained 3 % less sodium than the
benchmark soup.
Friedman analyses (according to the within-subject
design) for ranks and post hoc comparisons were conducted to determine if there were significant differences
between the amounts of salt participants added after
tasting soups with (i) different labels and (ii) different
levels of sodium reduction. Statistics were performed with
the statistical software package PASW Statistics version 18
(IBM, Armonk, NY, USA).
Results
Participants
The majority of participants were below the age of 40
years and well educated. More than half of the participants stated that health labels influenced their purchase
decision (see Table 1).
Expected liking and salt intensity
Expected liking
All soups were expected to be liked, with scores between
4?4 and 5?3 on a 9-point hedonic scale. Participants
tended to expect the soups with the reduced-salt label
to be less liked than the same soups without labels
(0?05 , P , 0?10). No statistically significant differences
were observed between the different soups with the same
Table 1 Characteristics of the study participants
Characteristic/category
Mean
SD
Age (years)
Females (n 33)
Males (n 17)
35?8
34?4
14?5
13?3
n
% of total
Education level
Secondary education or below
Tertiary education
Postgraduate or higher
Check the nutrition information when shopping
Always
Often
Sometimes
Rarely
Never
Labeling affects my food purchase
Always
Often
Sometimes
Rarely
Never
7
19
24
14
38
48
14
21
4
0
11
28
42
8
0
22
11
20
2
1
16
22
40
4
2
32
Effect of labels on taste and salt use
5
Table 2 Mean expected and perceived liking and salt intensity for the benchmark, 15 % and 30 % sodium-reduced soups with the three
different labels
Expected liking before tasting
Benchmark
Mean
No label
Tick label
Reduced-salt label
a
4?9
4?8a,b
4?4b
SD
1?6
1?3
1?5
15 % sodium
reduced
Mean
a
5?1
4?8a
4?5b*
SD
1?5
1?4
1?3
Perceived liking after tasting
30 % sodium
reduced
Mean
SD
a
5?3
5?2a
4?8b*
1?5
1?2
1?4
Expected salt intensity before tasting (on JRS)
Benchmark
Mean
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No label
Tick label
Reduced-salt label
6?24?33?6-
15 % sodium
reduced
Benchmark
Mean
a
4?5
4?7a
3?9b
SD
1?6
1?1
1?4
15 % sodium
reduced
30 % sodium
reduced
Mean
Mean
a
4?4
4?3a
5?5b
SD
1?4
1?6
1?6
a
4?0
4?0a
3?8a
SD
1?2
1?2
1?2
Perceived salt intensity after tasting (on JRS)
30 % sodium
reduced
Benchmark
15% sodium
reduced
30% sodium
reduced
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
1?4
1?2
1?2
6?34?33?6-
1
1?1
1?1
6?34?43?7-
1?4
1?2
1?1
6?86?25?5-
1?1
1?5
1?5
4?9
4?8
4?2-
1?0
1?4
1?3
4?13?63?4-
1?0
1?1
1?2
Liking was measured with a 9-point hedonic scale: 1 5 ‘not liked at all’ to 9 5 ‘extremely liked’.
Salt intensity was measured with a just-about-right scale (JRS): 1 5 ‘not salty enough at all’, 5 5 ‘just about the right amount of salt for me’, 9 5 ‘far too salty for me’.
a,b
Mean values within columns with unlike superscript letters were significantly different, as measured with a repeated-measures ANOVA (P , 0?05).
*Reduced-salt label soups tended to be different from soups without a label (P , 0?10).
-Significantly different from the just-about-right salt intensity which was set at 5, as measured with a one-sample t test (P , 0?05).
label in terms of expected liking across the 3 d of testing
(see Table 2). Participants were more willing to buy the
soups with the tick label (mean 5?4 (SD 1?6)) than the
benchmark soups without such label (mean 4?2 (SD 1?4);
P , 0?01).
soups which were 30 % reduced in sodium and carried
either the tick label (P , 0?01) or no health label (P , 0?01)
were less liked than the benchmark soups with these labels.
No such difference was observed for soups which carried
the reduced-salt label (see Table 2).
Expected salt intensity
Participants expected the soups without health labels to
be significantly above their ideal saltiness (mean range
6?2 to 6?3, i.e. too salty), whereas soups with health labels
were expected to be significantly below their ideal saltiness
(mean range 3?6 to 4?4, i.e. not salty enough; all P , 0?05).
No significant differences in expected salt intensity were
observed between the responses to the same packages on
the three different days (see Table 2).
Perceived salt intensity
All benchmark soups were perceived as significantly above
participants’ ideal salt concentration (mean range 5?5 to 6?8;
P , 0?05). The benchmark soup with the reduced-salt label
was perceived as significantly closer to participants’ ideal
salt intensity (mean 5?5 (SD 1?5)) than soups with either
the tick label (mean 6?2 (SD 1?5); P , 0?05) or no health
label (mean 6?8 (SD 1?1); P , 0?01). The benchmark soup
with the tick label was perceived as significantly closer to
participants’ ideal salt concentration than the same soup
without a health label (P , 0?05). Participants’ expectations
concerning salt intensity of the benchmark was significantly
positively associated with their perceived salt intensity
when the package did not carry the reduced-salt label
(no label r 5 0?50, P , 0?01; tick label r 5 0?32, P , 0?05;
reduced-salt label r 5 0?14, P 5 0?33; see also Table 2).
When consumers tasted the 15 % sodium-reduced
soups, the soup with the reduced-salt label was perceived
as significantly below participants’ ideal salt concentration (mean 4?2 (SD 1?3); P , 0?001), whereas the 15 %
sodium-reduced soup with the tick label (mean 4?8 (SD
1?4)) and that without a health label (mean 4?9 (SD 1?0))
were not perceived as significantly different from consumers’ ideal salt concentration. Expected and perceived
salt intensity of the 15 % sodium-reduced soup were significantly positively associated when the package carried
either the tick or the reduced-salt label (no label r 5 0?06,
Perceived liking and salt intensity
Perceived liking
When participants actually tasted the soups a strong
positive association between expected liking and perceived liking was observed for all soups across all labels
(all r between 0?44 and 0?86; all P , 0?001). Benchmark
soups were medium liked (mean range 3?9 to 4?7) and
significantly influenced by labels. That is, benchmark
soups with the reduced-salt label were less liked (mean
3?9 (SD 1?4)) than similar soups with no label (mean 4?5
(SD 1?6); P , 0?05) or the tick label (mean 4?7 (SD 1?1;
P , 0?01). Soups which were 15 % reduced in sodium and
carried the reduced-salt label were more liked (mean 5?5
(SD 1?6)) than similar soups with no label (mean 4?4
(SD1?4); P , 0?01) or the tick label (mean 4?3 (SD 1?6);
P , 0?01). Labels did not significantly influence participants’
liking for soups which were 30 % reduced in sodium. The
6
DG Liem et al.
P 5 0?66; tick label r 5 0?39, P , 0?01; reduced-salt label
r 5 0?33, P , 0?05).
All 30 % reduced-sodium soups were perceived as
below consumers’ ideal salt concentration (mean range
9
8
No health label
*
Reduced-salt label
Tick label
Perceived salt intensity
7
*
6
Adding salt
The number of participants who added salt after tasting
increased as the sodium reduction became larger (see
Table 3). In addition, those who added salt to their soup
generally added more salt when soups were further reduced
in sodium. For every soup (i.e. benchmark, 15 % reduced in
sodium, 30 % reduced in sodium), a greater number of participants added salt when the soup carried the reduced-salt
label than when the same soup carried either the tick label or
no health label. Those who added salt also added more salt
when soups carried the reduced-salt label (P , 0?05). When
sodium was reduced by 30 % and accompanied by the
reduced-salt label participants over-compensated the reduction in salt; this resulted in 8 % higher salt consumption than
when they consumed the benchmark soup (see Table 3).
*
5
4
3
2
s
re odi
du um
ce
d
30
%
%
s
re odi
du um
ce
d
15
B
en
ch
m
ar
k
1
Soup
Fig. 3 (colour online) Participants’ perceived salt intensity
(1 5 ‘not salty enough at all’, 5 5 ‘just about the right amount of
salt for me’, 9 5 ‘far too salty for me’) for benchmark, 15 % and
30 % sodium-reduced soups with the three different labels (no
health label, reduced-salt label and tick label). Values are
means with their standard deviations represented by vertical
bars. *Mean value was significantly different between soups
with the same sodium content: P , 0?05
Discussion
The present study suggests that when consumers are
able to taste the sodium reduction, a nutrient label which
states ‘now reduced in salt, great taste’ magnifies the
perceived difference in terms of ideal saltiness, and
consumers add more salt.
Table 3 Average amount of salt added and number of participants who added salt to the benchmark, 15 % and 30 % sodium-reduced soups
with the three different labels
Salt added (g)-
Benchmark
No label
Tick label
Reduced-salt label
15 % sodium reduced
No label
Tick label
Reduced-salt label
30 % sodium reduced
No label
Tick label
Reduced-salt label
% Na added relative to benchmark-
Significance of
differencey
n*
Mean
SD
Mean
SD
2
2
8
0?03
0?47
0?23
0?01
0?24
0?25
1?5
24?0
11?6
0?7
12?3
12?8
J
14
15
28
0?25
0?37
0?36
0?26
0?40
0?19
22?0
4?1
3?5
13?6
20?6
9?8
P , 0?05
30
35
46
0?58
0?57
0?75
0?36
0?27
0?32
20?3
20?8
8?3
18?3
13?9
16?6
P , 0?01
*Number of participants who added salt out of 50.
-Amount of salt added to 250 ml soup, calculated for those who did add salt.
-Calculated as {[(Na added1Na in soup)/Na in benchmark] 3 100 %} 2 100.
ySignificant difference between the labels as measured with a Friedman analysis for ranks.
JNo statistics were applied due to the low n.
-
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3?4 to 4?1; P , 0?001). The soup with the reduced-salt
label was, however, perceived as significantly further
from consumers’ ideal salt intensity (mean 3?4 (SD 1?2))
than the soups with either the tick label (mean 3?6 (SD
1?1); P , 0?01) or no health label (mean 4?1 (SD 1?0);
P , 0?01; see Fig. 3). Overall, perceived salt intensity
decreased with decreasing sodium concentration (all
P , 0?001). Expected and perceived salt intensity were
strongly associated when the package carried the
reduced-salt label, but not when other labels were present (no label r 5 0?28, P 5 0?05; tick label r 5 0?21,
P , 0?15; reduced-salt label r 5 0?66, P , 0?001).
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Effect of labels on taste and salt use
The effect of the reduced-salt label on perceived liking
is less clear. Potentially the negative expectation, generated by the reduced-salt label, may have created a pleasant surprise when consumers tasted the sodium-reduced
soup (i.e. ‘It’s not as bad as I thought it would be’). This
contrast effect did not seem to take place when soups
were further reduced in sodium, which elicited a clear
perceivable difference with the benchmark, nor was the
contrast effect evident when consumers were asked to
rate ideal saltiness or when they were asked to add salt
to optimize pleasantness of the soup. This may suggest
that overall liking is influenced by more aspects than
just saltiness.
Consumers can make a variety of foods more palatable
by adding precise amounts of table salt(20–23). Previous
studies in which participants added salt to sodiumreduced meals suggested that consumers compensated
only between 20 % and 22 % of the sodium which was left
out of the meal(24,25). This resulted in a meal with a lower
salt concentration than the original non-sodium-reduced
meal. In our study, consumers added larger amounts of
salt to the sodium-reduced soups, which resulted in soups
which contained about the same or higher amounts of
salt than the non-sodium-reduced soup. However, these
previous studies were conducted with whole meals
where salt is more likely to be on the surface after it has
been added from a salt shaker. This is in contrast with the
present study where salt was added to a liquid (soup).
It has previously been suggested that salt on the surface
of the food will elicit a higher salt intensity than salt
dissolved in food(26).
It is important to note that only 28 % of the participants
added salt to the 15 % sodium-reduced soups even
though no additional flavour-enhancing ingredients were
added by the manufacturer to compensate for the sodium
reduction. This means that, when sodium reduction is
compensated by other ingredients, a reduction of 15 % in
soups might be feasible as long as consumers are not
being made aware of the sodium reduction. Currently,
Unilever soups in Australia are in general 26 % lower in
sodium than similar soups in the USA and 7 % lower in
sodium than in the UK. This suggests that soups in for
example the USA could be lowered further in sodium,
preferably in small incremental steps, so that the salt
reduction is not perceived and consumer acceptance will
be maintained.
The present study was carried out in a laboratory
setting in which the information provided on the front of
the pack had little competition from other stimuli which
may attract consumers’ attention in a real shopping and
eating environment. Furthermore, our study sample
consisted of consumers below the age of 40 years. These
consumers might be more focused on taste and less
focused on health than older consumers, because older
aged consumers are more likely to have been in contact
with a variety of chronic diseases(27) and are more likely
7
(2)
to check nutrient information while shopping . It would
therefore be worthwhile to repeat the present study with
older consumers. Furthermore, our sample was in general
highly educated, which could have increased the number
of health-conscious consumers(28).
To our knowledge, research suggesting that front-ofpack labelling influences food choice has generally been
performed in markets in which a particular front-of-pack
label has recently been introduced. Consumers may pay
attention to these labels because they have been exposed
to heavy marketing around the logo(29). Longitudinal
studies in which the effectiveness of front-of-pack health
logos is investigated over time are lacking to our
knowledge. It could well be that, after a while, a front-ofpack logo loses the attention of consumers. Attention is
driven by consumers’ motivation, which is in line with
their driver of purchase(29). Future studies need to focus
on the influence of front-of-pack health logos, such as
the Heart Foundation Tick, on taste perception and liking
in an in-home setting, not only initially, but also after
repeated consumption over a longer time frame. Furthermore, it is recommended to assess the effectiveness of
health labels on long-term food purchase and consumption in markets where these labels are no longer supported by marketing.
Conclusions
A label that explicitly notifies consumers of a reduction
in sodium decreases the expected and perceived salt
intensity, and may increase the use of table salt, especially
when products are perceivably different in salt intensity. Overall health logos which do not emphasize the
reduction in salt are less likely to affect perceived salt
intensity and therefore are a viable solution to indicate the
healthiness of sodium-reduced products. This is a relatively new area of research, but already it is beginning to
deepen our understanding of how best to design and
market healthy choices.
Acknowledgements
Source of funding: This research was funded by a Deakin
Central Research Grant and supported by Unilever
Research. Conflict of interest: E.H.Z. works as a research
scientist at Unilever Research; D.G.L. is a senior lecturer at
Deakin University, F.M. is an MSc student at Deakin
University and R.S.J.K. is an associate professor at Deakin
University. Authors’ contributions: D.G.L. and F.M. contributed equally to the paper. D.G.L. was responsible for
the design, data analyses and manuscript; F.M. carried out
the study and contributed to the data analysis and
manuscript writing; E.H.Z. was involved in the design and
provided comments on earlier drafts of the manuscript;
R.K. provided comments on earlier drafts of the manuscript.
8
Acknowledgments: The authors would like to thank
Megan Cobcroft, Katherine Cook and Katherine Tocchini
for their technical assistance.
Public Health Nutrition
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